Complete common atrioventricular canal in infancy--surgical repair and postoperative hemodynamics.

Fourteen infants with complete common atrioventricular canal (CCAVC) underwent open heart surgery under deep hypothermia and circulatory arrest. There were three operative deaths and two late deaths. Postoperative studies performed in seven of the nine survivors revealed nearly normal hemodynamics. There were no residual shunts, and excellent mitral valve function was observed in six patients. In one patient, residual mitral regurgitation was noted. The pulmonary artery pressures and pulmonary vascular resistances were normal except in one who had severe pulmonary vascular obstructive disease before surgery. The mean left ventricular end-diastolic volume changed from 175 +/- 24% (SEM) before surgery to 106 +/- 7% after surgery (P less than 0.01). The corresponding right ventricular end-diastolic volume changed from 166 +/- 16% to 102 +/- 19% (P less than 0.025). Left ventricular ejection fraction was mildly decreased before and after surgery (0.63 +/- 0.02). Surgical repair of CCAVC is possible during the first year of life, with likely normalization of cardiac size and function. Unsatisfactory results related to pulmonary vascular obstruction may be anticipated if repair is delayed much beyond the first year.